---
session_id: "session_20260430_d9f3p1"
branch: "feat/domain-knot-libraries"
created_at: "2026-04-30T00:00:00Z"
current_mode: "plan"
version: "1.0"
---

## Session Overview

**Branch:** feat/domain-knot-libraries
**Started:** 2026-04-30 UTC
**Current Mode:** plan

## Mode History

| Mode | Entered | Exited | Summary |
|------|---------|--------|---------|
| plan | 00:00 | - | Designing domain knot libraries for DE/Analytics, Agentic Pipelines, ML Engineering |

## Actions Taken

### 2026-04-30 00:00 - plan mode
- Created branch feat/domain-knot-libraries from main
- Beginning PRD design for three domain knot library areas

## Context Summary

Planning standardized knot libraries for three domains:
1. Data Engineering / Analytics Engineering
2. Agentic Pipelines / Patterns
3. ML Engineering / Data Science

Codebase context: pirn uses @knot decorator or Knot subclassing. KnotRegistry allows global registration by name. Nodes directory has Source, Sink, Aggregator, Branch, Gate, SubTapestry, LoopSubTapestry. Examples exist for data_pipeline, llm_agent, financial, document_analysis, content_moderation.

## Notes
- No formal knot catalog exists yet
- Domain libraries will live under pirn/domains/ or similar
